Structurally reinforced macrocyclic ligands that show greatly enhanced selectivity for metal ions on the basis of the match in size between the metal ion and the macrocyclic cavity

Abstract

Addition of an extra bridging group between nitrogen donors on macrocyclic ligands to give a piperazine-like structure leads to much more rigid ligands which display selectivity for metal ions which is more strongly based on the match between the size of the metal ion and of the macrocyclic cavity than is the case for conventional macrocyclic ligands.